TY - JOUR
T1 - Emplacement and accumulation of magmatic products in contractional structures
T2 - How does it occur? Insights from Central Andes of northern Chile
AU - Martínez, F.
AU - Fuentes, G.
AU - Torres, C.
AU - Peña, M.
AU - Barraza, L. D.
N1 - Publisher Copyright:
© 2023 Elsevier Ltd
PY - 2023/7
Y1 - 2023/7
N2 - Structural and stratigraphic data demonstrate that the magmatism in northern Chile was accompanied by shortening related to the development of fold and thrust belts. However, how magmatic products were emplaced and accumulated in the contractional structures is an unresolved question. We, therefore, integrated field and seismic data from the regions of the Pampa del Tamarugal, Salar de Punta Negra Basin, and the Hornitos Fold and Thrust Belt to determine the main structures that facilitated the magma accumulation. The syn-kinematic granitic intrusions in the Hornitos Fold and Thrust Belt were preferably emplaced along fold-related thrusts. In this region, magma migrated along thrust ramps and finally accumulated into the core of the anticlines and broken synclines. Subsidiary and vertical tensional fractures controlled the magma accumulation in the hinge zone and at the axis of the folds. The seismic data from the Pampa del Tamarugal and Salar de Punta Negra Basin present evidence of buried volcanoes on inversion anticlines. During the tectonic inversion of the pre-existing Late Paleozoic to Mesozoic half-graben structures in the regions, magma migrated along the master faults and finally accumulated into the core of the inversion anticlines as sills or was expulsed to the surface as volcanoes, as evidenced by the Punta Negra Monogenetic Volcano.
AB - Structural and stratigraphic data demonstrate that the magmatism in northern Chile was accompanied by shortening related to the development of fold and thrust belts. However, how magmatic products were emplaced and accumulated in the contractional structures is an unresolved question. We, therefore, integrated field and seismic data from the regions of the Pampa del Tamarugal, Salar de Punta Negra Basin, and the Hornitos Fold and Thrust Belt to determine the main structures that facilitated the magma accumulation. The syn-kinematic granitic intrusions in the Hornitos Fold and Thrust Belt were preferably emplaced along fold-related thrusts. In this region, magma migrated along thrust ramps and finally accumulated into the core of the anticlines and broken synclines. Subsidiary and vertical tensional fractures controlled the magma accumulation in the hinge zone and at the axis of the folds. The seismic data from the Pampa del Tamarugal and Salar de Punta Negra Basin present evidence of buried volcanoes on inversion anticlines. During the tectonic inversion of the pre-existing Late Paleozoic to Mesozoic half-graben structures in the regions, magma migrated along the master faults and finally accumulated into the core of the inversion anticlines as sills or was expulsed to the surface as volcanoes, as evidenced by the Punta Negra Monogenetic Volcano.
KW - Andean forearc
KW - Basin inversion and magmatism
KW - Fold and thrust belts
KW - Northern Chile
KW - Shortening and magmatism
UR - http://www.scopus.com/inward/record.url?scp=85160415315&partnerID=8YFLogxK
U2 - 10.1016/j.jsg.2023.104879
DO - 10.1016/j.jsg.2023.104879
M3 - Article
AN - SCOPUS:85160415315
SN - 0191-8141
VL - 172
JO - Journal of Structural Geology
JF - Journal of Structural Geology
M1 - 104879
ER -